1.1 This standard specifies the water quality items, standard values, evaluation of water quality and analysis method of water quality items as well as implementation and supervision of standard based on the environmental function classification and protection target of surface water 1.2 This standard is applicable to rivers, lakes, canals, channels, reservoirs and other surface water areas with utilizable functions within People’s Republic of China. The water areas with specific functions shall comply with corresponding professional water quality standards.
2 Normative References
"Specification for Drinking Water Quality" (issued by the Ministry of Health in 2001) as well as other standards and codes for analysis methods listed in Tables 4~6 contain provisions which, through reference in this text, constitute provisions of this standard, and have the same effect as this standard. If the above-mentioned standards and codes are revised, their latest edition shall apply.
3 Classification of Water Area Functions and Standards
The surface water area is divided into five classes according to its environmental function and protection target.Class I: mainly for source of water and national nature protection areas;
Class II: mainly for Class I protection areas for surface water sources of centralized drinking water, habitats for rare aquatic, spawn ground for fishes and shrimps as well as feeding ground for young fishes;
Class III: mainly for Class II protection areas for surface water sources of centralized drinking water, wintering ground or fishes and shrimps, migration pathway, aquiculture area as well as other fisheries area and swimming area;
Class IV: mainly for general industrial water areas and entertainment water areas not directly touched by human body;
Class V: mainly for farmland water areas and water areas for general landscape requirement.
To correspond to the above-mentioned five water area functions of surface water, the standard values for basic items of environmental quality standards for surface water are divided into five classes. Different classes of functions shall company with corresponding standard values. The standard values for higher classes of water area functions are stricter than those for lower classes water area functions. If there are several classes of functions in the same water area, the standard value for the highest class of function will be taken. To realize water area functions has the same meaning as to reach function classification standards.
